Davros,
Please look at the Spinal Kinetics M6.
If I can get pre-authorization from BC World, I will have three of these.
They best mimick the natural movement of the (natural) disc.
The ball and socket, seem to cause much unnatural movement, and cause (hypertrophy, I know, I have this already) (wear and tear) on the facet joints.
The M6, has motion in six degrees, hence, the name M6.
There are many that can put this in, and have implanted thousands.
Will not recommend who you should see, but if you send me Private, I can give you more details and who I will go see.
All the Best, one issue for sure, this is a game changer.